Variable capacity storage unit for commodities

ABSTRACT

Packets ( 2 ) transferred from a packing machine to an overwrapping machine pass through an in-line storage unit ( 1 ) of variable capacity internally of which they are directed along a path (P) bet ween a loading station ( 3 ) and an unloading station ( 4 ); the unit ( 1 ) consists in a succession of conveying members ( 19 ) each set in motion by a corresponding motor ( 30 ), and chutes ( 44 ) by which the conveying members ( 19 ) are linked in series.

TECHNICAL FIELD

[0001] The present invention relates to a storage unit of variablecapacity for commodities.

[0002] The invention disclosed relates to a storage unit of variablecapacity designed for installation in-line between an upstream machineand a downstream machine, such as will accumulate and/or release avariable number of commodities, and in particular packets of cigarettes,to which explicit reference is made throughout the followingspecification albeit with no limitation in scope implied.

BACKGROUND ART

[0003] It is standard practice in the tobacco industry for an upstreammachine, typically a packer, to be linked to a downstream machineconsisting generally in a cellophaner, by way of a variable capacitystorage unit able to function as a reservoir for packets passing fromthe one machine to the other. Such a reservoir is in fact able tocompensate both for an interruption or reduction in the supply ofpackets to the cellophaner, occasioned for example by a stoppage or amomentary drop in tempo of the packer, and for an insufficient uptake ofpackets turned out by the packer as a result of a stoppage or drop intempo of the cellophaner.

[0004] With a reservoir of variable capacity between the packer and thecellophaner, accordingly, it becomes possible to ensure that a stoppageor drop in tempo of either machine will not adversely affect theoperation of the system of which the two machines form a part, at leastfor a time dependent on the capacity of the storage unit employed.

[0005] Finding application to advantage among variable capacity storageunits embraced by the prior art is the type identified asfirst-in-first-out, or FIFO, in which the packets first to be taken upare also the packets first to be released. In familiar FIFO units, thepackets advance in an ordered succession along a path extending betweena loading station and an unloading station. The number of packets in thestorage unit at any given moment, and therefore the capacity of thereservoir, will vary with the variation in ratio between the number ofpackets fed in and the number of packets released, per unit of time.

[0006] One such conventional variable capacity storage unit appearssubstantially as a single continuous conveyor of helical geometryconsisting for example in a flexible power driven belt coinciding withthe aforementioned path and capable of advancing the packets from theloading station to the unloading station.

[0007] To ensure a continuous supply of packets to the cellophaner whenusing a storage unit of this type, the appropriate distributioninternally of the unit is maintained in such a manner that the packetsare ordered in a continuous column; consequently, the capacity of thereservoir is dictated by the length of the path, which can be variedonly through the agency of external means such as will allow thepositions of the loading station and the unloading station to be movedin relation to the path.

[0008] Accordingly, and significantly, in the event that the rate atwhich the packets are taken up by the cellophaner is slower than therate at which the packets are turned out by the packer, there will be acall for the reservoir to increase its capacity, with the result thatthe column of packets forming gradually at the infeed station of thecellophaner, and in the storage unit itself, becomes longer and longer.

[0009] The stresses to which the packets making up the column aresubjected will increase as the length of the column gradually increases,especially at the end nearest the infeed of the cellophaner; indeedbeyond certain limits the consecutive packets will strike one anotherand the stresses attributable to sliding contact are of an order such asto cause damage to the contents.

[0010] It will be clear that first-in first-out storage units of thistype betray serious limitations as regards both their capacity and thevariation of their capacity, and are able thus to compensate forimbalances in throughput between the machines of a system for shortperiods only.

[0011] The object of the present invention is to provide a storage unitof variable capacity for commodities that will be free of the drawbacksmentioned above, yet simple from the constructional standpoint, in whichpackets can be transferred from the loading station to the unloadingstation without suffering damage.

DISCLOSURE OF THE INVENTION

[0012] The stated object is realized in a storage unit of variablecapacity for commodities, establishing a path along which thecommodities are caused to advance between a loading station and anunloading station, characterized in that it comprises at least twoconveying members associated each with drive means serving to set theselfsame conveying members in motion, and means by which to link theconveying members in series.

[0013] The invention will now be described in detail, by way of example,with the aid of the accompanying drawings, in which:

[0014]FIG. 1 illustrates a storage unit for packets of cigarettesaccording to the present invention, shown schematically and inperspective;

[0015]FIG. 2 illustrates the storage unit of FIG. 1, schematically andin perspective, and with certain parts omitted for clarity;

[0016]FIG. 3 illustrates the storage unit of FIG. 2 in a schematic sideelevation;

[0017]FIG. 4 shows an enlarged detail of FIG. 2, viewed schematicallyand in perspective;

[0018]FIG. 5 shows the same enlarged detail as in FIG. 4 in a schematicside elevation with certain parts in section and others omitted;

[0019]FIG. 6 shows another enlarged detail of FIG. 2 viewedschematically and in perspective;

[0020]FIG. 7 shows a further enlarged detail of FIG. 2, viewedschematically and in perspective;

[0021]FIG. 8 shows a detail of the storage unit in FIG. 1, illustratedin an alternative embodiment, viewed schematically in plan and withcertain parts omitted;

[0022]FIG. 9 and FIG. 10 show a detail of FIG. 8, enlarged and in twoschematic sectional views taken on different cutting planes denotedIX-IX and X-X respectively;

[0023]FIG. 11 shows a detail of FIG. 8, viewed schematically and inperspective with certain parts omitted;

[0024]FIG. 12 shows the detail of FIG. 11, viewed schematically and inperspective with certain parts omitted, and including a furthercomponent.

[0025] Referring to FIGS. 1, 2 and 3 of the drawings, 1 denotes astorage unit, in its entirety, such as will contain a variable number Nof commodities, consisting preferably in packets 2, and transfer theselfsame packets 2 between a loading station 3 and an unloading station4 along a predetermined path P, in a predetermined direction D.

[0026] Observing FIGS. 1 and 2, the loading station 3 is located at theoutfeed 5 of a cigarette packer indicated as a block denoted 6 in FIG.3, and the unloading station 4 is located at the infeed 7 of acellophaner indicated by a block denoted 8 likewise in FIG. 3.

[0027] The packets 2, each of which exhibiting two main side faces 9,two smaller flank faces 10 and two end faces 11, are directed from thepacker 6 into the storage unit 1 by way of the loading station 3 andreleased from the unit 1 to the cellophaner 8 by way of the unloadingstation 4.

[0028] The storage unit 1 is a first-in first-out (FIFO) type,signifying that a given packet 2 fed in first at the loading station 3is also the first packet to be released at the unloading station 4.

[0029] The storage unit 1 is essentially cylindrical in appearance, witha predominating vertical axis 1 a, and comprises a frame 12 having threeuprights 13, 14 and 15 of which the bottom ends are fitted withrespective floor mounts 16 and the ends uppermost are connected to a topcircular bracing hoop 17 occupying a plane perpendicular to the axes ofthe uprights 13, 14 and 15.

[0030] The frame 12 further comprises a bottom circular bracing hoop 18(FIGS. 2 and 3) disposed parallel to the top hoop 17 and of identicaldimensions, to which the uprights 13, 14 and 15 are connected at a shortdistance above the floor mounts 16.

[0031] The storage unit 1 is compassed between the two circular hoops 17and 18 and comprises a plurality of conveying members 19 ordered insuccession along the vertical axis 1 a, occupying respective mutuallyparallel planes spaced-apart one from the next and disposed transverselyto the selfsame axis 1 a.

[0032] Referring to FIGS. 2, 4, 5 and 6, the conveying members 19function as independent storage modules of the storage unit 1, appearingas a succession of mutually coaxial circular elements centred on thevertical axis 1 a.

[0033] Each conveying member 19 follows a looped path P1 and comprisesan internal horizontal annular web 20 of which an outer edge 20 b isjoined to a vertical cylindrical side wall 21 functioning as a supportfor two annular channels 22, and an inner edge 20 a presents adownwardly directed rim 23.

[0034] In the example of FIGS. 3, 4, 5 and 6, each of the two annularchannels 22, which occupy mutually parallel planes, appears as a shelf24 affording an annular way 25 on which the packets 2 lie disposedlongitudinally; more precisely, the annular way 25 is fashioned with acentral annular depression 26 that serves to reduce the area of contactbetween the annular way 25 and the corresponding main side face 5 of thepacket 2.

[0035] Each annular way 25 is compassed internally and externally byrespective vertical annular walls 62 and 63 set apart by a distancemarginally greater than the transverse dimension of a single packet 2.

[0036] As discernible from FIGS. 2 and 6, the internal annular web 20 ofeach conveying member 19 affords a downwardly directed surface 27 by wayof which it is supported on respective freely revolving bearing rollers28. The rollers 28 are mounted in turn to the uprights 13 and 15 by wayof respective angle brackets 29 of which the shorter leg is associatedrigidly with the relative upright.

[0037] As illustrated in FIGS. 1, 2, 4, 5 and 8, each individualconveying member 19 is associated with a relative motor 30 by which itcan be set in motion about the axis 1 a of the storage unit 1.

[0038] Referring to FIGS. 4 and 5 in particular, each motor 30 ismounted to a plate 31 connected rigidly in turn to a rail 32 slidable onone upright 14, occupying a position with the respective axis 30 aradially disposed relative to the storage unit 1 and intersecting thevertical axis 1 a.

[0039] The output shaft 33 of each motor 30 carries a respective keyedwheel 34 offered in contact to the aforementioned surface 27 of theannular web 20 and combining thus with the freely revolving rollers 28carried by the remaining two uprights 13 and 15 to support the relativeconveying member 19.

[0040] The keyed wheel 34 is made of resilient material and operates inconjunction with a freely revolving pinch roller 35 rotatable about anaxis parallel to the axis 30 a of the motor 30; the pinch roller 35 ispositioned on the side of the internal annular web 20 opposite to thekeyed wheel 34 and carried by the free end 36 of an arm 37 connectedrotatably by the opposite end 38 to a pivot 39, associated rigidly withthe rail 32, of which the axis extends transversely to the axis 30 a ofthe motor 30.

[0041] The pinch roller 35, likewise made of a resilient material, isplaced in contact with the upwardly directed surface 40 of the internalannular web 20 and operates in conjunction with the keyed wheel 34 insuch a way that the conveying member 19 can be driven by frictionwithout any slipping contact between the wheel 34 and the annular web20.

[0042] In practice therefore, the keyed wheel 34 and the relativesurface 27 are clutch-coupled in such a way as to drive the relativeconveying member 19 in rotation about the axis 1 a of the storage unit1.

[0043] Observing FIGS. 1, 2, 3 and 6, it will be seen that the frame 12of the unit 1 further comprises a pair of C-shaped bars 41 extendingparallel to the axis 1 a and connected by way of respective arms 42 ateach end to the top and bottom bracing hoops 17 and 18.

[0044] The bars 41 serve to support means 43 by which the annularchannels 22 of the conveying members 19 are linked one to the next. Moreexactly, each of the linking means 43 comprises a relative chute 44 bywhich the annular way 25 of a given channel 22 is connected to theannular way 25 of the channel next in succession with no break incontinuity. The linking means 43 thus serve to connect each annularchannel 22 with the next annular channel 22, be it a connection betweenchannels forming part of one conveying member 19 or channels belongingto two distinct conveying members, in such a way that the path Pfollowed by the packets 2 internally of the storage unit 1 is renderedcontinuous.

[0045] In particular, each chute 44 comprises propulsion means 45 usingcompressed air, by which the single packets 2 are conveyed along thechute 44, the ends 44 a and 44 b of the chute being shaped in such a wayas to afford an ascent ramp 76 and a descent ramp 77, respectively,creating a seamless join between the annular ways 25 of theinterconnected annular channels 22 and facilitating the passage of apacket 2 from one annular channel 22 by way of the ascent ramp 76 ontothe chute 44 and thence by way of the descent ramp 77 onto the channel22 next in succession.

[0046] The positioning of the chute 44 relative to the annular channel22 is such that the end denoted 44 a coincides with an exit position 46at which the packets 2 run off the one channel 22, and the end denoted44 b with an entry position 47 at which the packets 2 run onto the nextannular channel 22.

[0047] Referring to FIGS. 6 and 7, in particular, each chute 44 alsoincorporates relative manifold means denoted 58 in their entirety and,as illustrated to best advantage in FIG. 7, comprising two mutuallyparallel walls 48 and 49 of which the uppermost, denoted 48 in FIG. 7,affords the surface on which the packets 2 slide along the chute 44.

[0048] The two walls 48 and 49 are joined at the two ends 44 a and 44 bof the chute 44 and form the top and bottom sides of a chamber 50enclosed laterally by two vertical walls 60 and 61 extending along thechute 44, of which two free edges project above the sliding surfaceafforded by the top wall 48. The chamber 50 is connected by way of aduct 51 on the side of one vertical wall 60 with a source 59 ofpressurized fluid, and by a plurality of holes 52 with the slidingsurface of the top wall 48. The holes 52 are inclined at an angle ofless than 90° along the direction D followed by the packets 2 anddistributed uniformly along the sliding surface of the top wall 48, insuch a way as to gather a flow of air from the pressurized source 59into jets G constituting the propulsion means 45 by which the packets 2are advanced.

[0049] As illustrated particularly in FIG. 2 and in FIG. 6, the storageunit 1 also includes a master controller 53 interlocked to a pluralityof sensors denoted 54 in their entirety and numbering at least one foreach conveying member 19. The sensors 54 are designed to generaterespective output signals both indicating the proximity of the packets 2and identifying the position occupied by each packet 2 relative to thepackets preceding and following along each annular channel 22 of eachconveying member 19, and to send these same signals to the controller53.

[0050] More exactly, the sensors 54 in question could be photocells, byway of example, and will include one sensor 55 located at the entryposition 47 of each conveying member 19, another sensor 56 covering theloading station 3 and a further sensor 57 covering the unloading station4, designed respectively to indicate the extent to which the singleconveying member 19 has been filled, the number of packets 2 admitted tothe storage unit 1, and the number of packets 2 released from the unit1.

[0051] The controller 53 is also connected on the output side to each ofthe motors 30 and responds to the information received from the singlesensors 54 by trimming the speed at which the conveying member 19rotates about the axis 1 a of the unit 1, thereby controlling the rateat which the packets 2 are advanced along each conveying member 19 inrelation to the feed rate of the packets 2 revolving on the nextconveying member 19 in sequence, in such a way as to verify and regulatethe extent to which the conveying member 19 is filled.

[0052] In the example of FIGS. 8 to 12, the annular way 25 afforded bythe shelf 24 of each channel 22 presents a flat surface 64 compassedinternally and externally by respective vertical annular walls 62 and 63as aforementioned. In addition, a flexible annular foil 65 is associatedwith each annular channel 22, anchored by way of an internal edge 66 tothe flat surface 64 and disposed normally in contact with this samesurface 64 as illustrated in FIG. 9.

[0053] Also associated with each annular channel 22 are deflector means67 interposed between the flat surface 64 of the annular way 25 and thefoil 65 at a location coinciding with the linking means 43.

[0054] Referring to FIGS. 8, 10 and 11, each of the deflector means 67consists in a curved strip 67 occupying a fixed position substantiallybreasted with the external vertical annular wall 63 and with the flatsurface 64 afforded by the annular way 25 of the relative annularchannel 22; considered in the direction of rotation followed by theconveying members 19 (anticlockwise as seen in the drawings) the curvedstrip 67 exhibits a first portion 68 of ascending wedge profile, asecond portion 69 of constant height equal to the height of the externalvertical wall 63 of the annular channel 22, and a third portion 70 ofdescending wedge profile.

[0055] As discernible in FIG. 8 and FIG. 11, the ascending first portion68 is located immediately preceding the exit position 46 of therespective annular channel 22, whilst the second portion 69 of constantheight coincides with an arc T extending between the exit and the entrypositions 46 and 47, and the descending third portion 70 is locatedimmediately beyond the entry position 47 of the selfsame annular channel22.

[0056] With reference to FIGS. 10 and 11, the curved strips 67 aresupported by a common frame 78, to which they are connected byrespective brackets 76, occupying a fixed position and alignedvertically on the predominating axis 1 a of the storage unit 1.

[0057] Referring to FIGS. 8 and 12, the aforementioned linking means 43are carried by a common frame 73 supported by a shaft 74 disposed withits axis 75 parallel to the axis 1 a of the storage unit 1, andsupported in its turn by respective top and bottom arms 80 connected tothe frame 12 of the unit. The frame 73 is pivotable about the axis 75between an operating position, illustrated in FIG. 12, in which twoadjacent channels 22 are interconnected by the respective linking means43 and the ends 61 a of the internal vertical wall 61 associated withthe respective chute 44 project above the adjacent annular channel 22 tofunction as means by which the packets 2 are diverted, and anon-operating position disengaged from the relative conveying members 19as illustrated in FIG. 8, which in the interest of aiding thedescription also shows one of the linking means 43 in the operatingposition.

[0058] The operation of the storage unit 1 will now be describedassuming the unit itself to be empty and the upstream and downstreammachines 6 and 8 both operational, so that packets 2 of cigarettes canbe directed into the storage unit 1 from the packer 6 by way of theloading station 3, and taken up by the cellophaner 8 at the unloadingstation 4.

[0059] The packets 2 typically must be released from the reservoir atintervals timed to coincide exactly with the movements of the workingparts utilized in the cellophaner 8, and particularly the components(not illustrated, being of familiar type) by which the single packets 2are picked up; to this end, when transferred from the last conveyingmember 19 in sequence to the infeed 7 of the cellophaner 8, the packets2 will be made to pass along a linking conveyor (not illustrated)connected to a pickup station of the cellophaner 8, and decelerated bybraking means (likewise not illustrated) in such a way as to form acontinuous column of packets 2 advancing with no gap between one and thenext.

[0060] Accordingly, the conveying member 19 connected to the infeed 7 ofthe cellophaner 8 at the unloading station 4 will be set in rotation bythe relative motor 30 at a low peripheral speed, so that the packets 2occupying the annular channels 22 are made to advance in relativelyclose order. This is illustrated by way of example in FIGS. 1 and 2,where D1 denotes a comparatively short distance between one packet 2 andthe next.

[0061] By contrast, the conveying member 19 connected to the outfeed 5of the packer 6 is set in rotation by the relative motor 30 at aperipheral speed higher than the speed of the final conveying member 19in sequence, and in any event no less than the speed at which thepackets 2 pass through the outfeed 5.

[0062] In the example illustrated, the peripheral speed induced in thefirst conveying member 19 by the relative motor 30 is higher than theinitial speed at which the packets 2 leave the packer 6, so that thesuccessive packets 2 can be taken up correctly from the packer 6 by theconveying member 19 and spaced apart one from the next by apredetermined distance. Thus, the distance D2 that separates the packets2 carried by the first conveying member 19 in sequence, connected to theloading station 3, is greater than the distance D1 between the packetson the final conveying member 19 in sequence connected to the unloadingstation 4.

[0063] The packets 2 directed into the storage unit 1 by way of theloading station 3 are transferred from one conveying member 19 to thenext, through to the unloading station 4.

[0064] To fill the storage unit 1 with packets 2 in as short a time aspossible and begin supplying the cellophaner 8, the speed of the singleconveying members 19 can be increased progressively, in which case thedistance between successive packets 2 when transferred from a slowerconveying member 19 to a faster conveying member 19 will be increasedwith each passage.

[0065] As the packets 2 approach the unloading station 4 however, theymust be brought nearer to one another and therefore transferred from afaster conveying member 19 to a slower conveying member 19, so that whenreleased at the infeed 7 of the cellophaner 8 they will be arranged inrelatively close order.

[0066] In the event of the cellophaner 8 stopping and the packer 6continuing to operate, the packets 2 are brought to a standstill on thefinal conveying member 19 as a queue forms at the infeed 7 of themachine 8, although the controller 53 will continue to pilot themovement of the conveying member 19 at minimum speed as the queueaccumulates, until the relative sensor 55 covering the entry position 47signals that this final conveying member 19 of the unit 1 is full.

[0067] The controller 53 responds by stopping the final conveying member19, now full up, and decelerating the preceding conveying members 19progressively. More exactly, the conveying member 19 immediatelypreceding the member just brought to a halt will continue operating atminimum speed before stopping in similar fashion; in this way, beginningwith the conveying member 19 located near to the unloading station 4, aseach conveying member 19 is filled, the preceding conveying member 19 isdecelerated and brought ultimately to a halt, continuing thus insequence until the entire reservoir is full.

[0068] In this situation, therefore, which contrasts with the normalconveying situation on the annular channel 22 of each conveying member19, when there is no sliding contact between the packets 2 and thechannel 22, the packets 2 will now begin sliding against the annular way25 of the shelf 24, albeit the sliding contact occurs at an appreciablylow rate of feed and only for the length of the path P compassed by theindividual conveying member 19.

[0069] The sliding action thus affects only a limited number of thepackets 2, which advance at minimum speed along a path of length suchthat the sliding movement will occasion no damage to the packets 2,thereby avoiding any deterioration attributable to impact andcompression forces generated between the adjacent end faces 11 of thepackets 2.

[0070] As discernible from the foregoing, each conveying member 19constitutes an independent storage module and the distance between twosuccessive packets 2, determined by the rate of feed along the singleconveying member 19, reflects the capacity of the reservoir toaccommodate additional packets 2. In other words, the operating marginof the storage unit 1, in terms of its capacity, is dependent on thedifference between the distance D2 separating two successive packets 2induced initially on the first conveying member 19 connected to theloading station 3, and the distance D1 separating packets 2 on the finalconveying member 19 connected to the unloading station 4, when inoperation and driven by the relative motor 30.

[0071] The speed at which the single conveying member 19 rotates isdetermined by the master controller 53, interlocked to the sensors 54,55, 56 and 57, and will be regulated in such a way as to advance thepackets 2 along the path P, varying the distance that separates each onefrom the next between the two aforementioned values D2 and D1 inaccordance with the prevailing feed and storage requirements.

[0072] Accordingly, the distance between two successive packets 2 willvary “concertina” fashion according to the throughput required at anyone time.

[0073] In the event of the packer 6 stopping and the cellophaner 8remaining in operation, the conveying members 19 will continue to supplypackets 2 at the operating tempo of the cellophaner 8 for a givenduration.

[0074] The operation of the storage unit 1 in the case of the exampleillustrated in FIGS. 8 to 12 is the same in all respects as that alreadydescribed referring to the example of FIGS. 1 to 7, the one differencebeing in the way that the packets 2 are caused to leave the one annularchannel 22 and join the next channel 22 in sequence. In this instance,in effect, with the annular channel 22 rotating anticlockwise, theassociated foil 65 is engaged by the deflector strip 67 and caused toflex gradually in such a way that an external portion 71 of the foil isshifted away from a position occupying the same plane as the annular way25, as illustrated in FIG. 9, and toward a position as illustrated inFIG. 10 in which the external portion 71 occupies substantially the sameplane as the chute 44 of the linking means 43. In this way, packets 2near the exit position 46 of a given annular channel 22 are divertedinitially by the end 61 a of the internal vertical wall 61 and directedthrough the effect of centrifugal acceleration along the portion 71 ofthe foil 65 currently in the flexed configuration, and occupyingsubstantially the same plane as the chute 44, toward the entry of therelative linking means 43. At the entry position 47 of an adjacentchannel 22, similarly, the packets 2 are directed into the channel 22 bypassing along the portion 71 of the foil 65, which in this instancelikewise will be in the flexed configuration, lying above the annularwall 63 and occupying the same plane as the chute 44.

1. A storage unit (1) of variable capacity for commodities (2) affordinga path (P) along which commodities (2) are caused to advance between aloading station (3) and an unloading station (4), characterized in thatit comprises at least two conveying members (19) associated each withdrive means (30) serving to set the selfsame conveying members (19) inmotion, and means (43) by which to link the conveying members (19) inseries.
 2. A storage unit as in claim 1, comprising a plurality ofconveying members (19).
 3. A storage unit as in claim 1 or 2, whereineach conveying member (19) extends along a respective path (P1)describing a closed loop and is set in motion along the selfsame path(P1) through the agency of the respective drive means (30).
 4. A storageunit as in claims 1 to 3, wherein each conveying member (19) occupies arespective geometrical plane.
 5. A storage unit as in claim 4, whereinthe conveying members (19) occupy respective planes disposed parallelone with another.
 6. A storage unit as in claims 1 to 5, presenting apredominating geometrical axis (1 a), wherein the conveying members (19)are disposed in succession along the predominating axis (1 a).
 7. Astorage unit as in claims 1 to 6, wherein each conveying member (19)appears as a circular element comprising at least one annular web (20)associated with the respective drive means (30) and at least one annularchannel (22) supporting the commodities (2).
 8. A storage unit as inclaim 7, wherein the conveying member (19) comprises at least twoannular channels (22) occupying respective mutually parallel planes andcoaxial one with another.
 9. A storage unit as in claim 7, wherein theconveying members (19) are coaxial one with another and with thepredominating axis (1 a).
 10. A storage unit as in claims 1 to 9,wherein each of the conveying members (19) presents an entry position(47) and an exit position (46), both determined by the linking means(43), at which the commodities (2) are received from a preceding annularchannel (22) and released to a successive annular channel (22),respectively.
 11. A storage unit as in claim 10 where dependent on claim8, wherein the at least two annular channels (22) are interconnected bythe linking means (43).
 12. A storage unit as in claims 1 to 11, whereinthe linking means (43) comprise at least one connecting chute (44)interconnecting each two consecutive annular channels (22).
 13. Astorage unit as in claims 7 to 12, wherein each conveying member (19)comprises at least one annular channel (22) presenting an annular way(25) compassed internally and externally by respective vertical annularwalls (62, 63), also an annular foil (65) positioned over the annularway (25) and permanently associated with the channel (22).
 14. A storageunit as in claim 13, wherein the foil (65) is anchored by an internaledge (66) to a flat surface (64) of the annular way (25) presented bythe relative annular channel (22) and associated with stationarydeflector means (67) interposed between each annular channel (22) andthe relative foil (65) in a position of close proximity to the externalvertical annular wall (63), presenting a first portion (68) of ascendingwedge profile and thereafter, considered in the direction of rotationfollowed by the conveying members (19) around the predominating axis (1a), a second portion (69) of constant height substantially equal to theheight of the external vertical wall (63) of the annular channel (22),extending at least through the exit position (46) of the relativeannular channel (22).
 15. A storage unit as in claim 14 where dependenton claims 5 and 6, wherein each of the deflector means (67) presents anascending first portion (68) located immediately preceding the exitposition (46) of a respective annular channel (22), a second portion(69) of constant height coinciding with an arc (T) extendingsubstantially between the exit position (46) and the entry position(47), and a descending third portion (70) located beyond the entryposition (47), relative to the direction of rotation followed by theconveying members (19) about the predominating axis (1 a).
 16. A storageunit as in claims 11 to 15, wherein the annular foil (65) is caused toflex elastically on encountering the second portion (69) of constantheight presented by the deflector means (67), in such a manner that anexternal portion (71) of the foil occupies substantially the same planeas the chute (44) of the respective linking means (43).
 17. A storageunit as in claims 13 to 16, wherein the flat surface (64) of the annularway (25) presented by each annular channel (22) affords a plurality ofangularly equispaced open slots (72).
 18. A storage unit as in claim 12,wherein the at least one chute (44) incorporates respective propulsionmeans (45) by which the commodities (2) are caused to advance along theselfsame chute.
 19. A storage unit as in claim 18, wherein propulsionmeans (45) consist in jets (G) of a pressurized fluid.
 20. A storageunit as in claim 18 or 19, wherein the chute (44) comprises respectivemanifold means (58) associated with the propulsion means (45).
 21. Astorage unit as in claim 20, wherein manifold means (58) comprise twowalls (48, 49), one of which affording a surface slidably supporting thecommodities (2), joined together at the ends (44 a, 44 b) of the chute(44) and compassing a chamber (50) connected on the one hand to a source(59) of pressurized fluid and on the other to a plurality of pin holes(52) distributed uniformly along the surface of the wall (48) slidablysupporting the commodities (2).
 22. A storage unit as in claim 21,wherein the chamber (50) is enclosed by two vertical walls (60, 61) oneon either side, bordering the sliding surface afforded by the top wall(48), of which at least one vertical wall (61) exhibits two oppositeends (61 a) projecting above the respective adjacent annular ways (22)and affording means by which to divert the commodities (2).
 23. Astorage unit as in claims 1 to 22, wherein to the linking means (43) arecarried by a common frame (73) supported by a shaft (74) of which theaxis (75) is disposed parallel to the predominating axis (1 a), androtatable thus about the selfsame axis (75) between an operatingposition in which the respective conveying members (19) are linked, anda non-operating position of disengagement distanced from the conveyingmembers.
 24. A storage unit as in claim 3, wherein the drive means (30)comprise a wheel (34) engaging a surface (27) of the annular web (20).25. A storage unit as in claim 17, comprising pinch rollers (35)associated one with each of the drive means (30), operating inconjunction with the wheel (34) and offered in contact to a surface (40)of the annular web (20) opposite to the surface (27) engaged by thewheel (34).
 26. A storage unit as in claim 24 or 25, wherein drive istransmitted from the wheel (34) to the annular web (20) by friction. 27.A storage unit as in claims 1 to 26, comprising a master controller (53)interlocked to a plurality of sensing means (54) corresponding in numberto the number of single conveying members (19), such as will generaterespective output signals both indicating the proximity of thecommodities (2) and identifying the position occupied by each commodityrelative to the commodities preceding and following along each annularchannel (22) of each conveying member (19), and send the signals to thecontroller (53).
 28. A storage unit as in claim 27, wherein the mastercontroller (53) is connected on the output side to each of the drivemeans (30) in such a manner as to regulate the speed at which the singleconveying members (19) rotate about the axis (1 a) according to theinformation in the output signals received from the sensing means (54)and to control the rate at which the commodities (2) advance on eachconveying member (19), thereby verifying and controlling the extent towhich each conveying member (19) is filled.
 29. A variable capacitystorage unit for commodities, substantially as described with referenceto the figures of the accompanying drawings.